The `RegisterClient` function previously deduplicated the list of models provided by a client. This could lead to an inaccurate representation of the client's state if it intentionally registered the same model ID multiple times. This change refactors the registration logic to store the raw, unfiltered list of models, preserving their original order and count. A new `rawModelIDs` slice tracks the complete list for storage in `clientModels`, while the logic for processing changes continues to use a unique set of model IDs for efficiency. This ensures the registry's state accurately reflects what the client provides.